[A portion of these plants were referred by me to Dr. Newberry for examination, and he has given the following list of them. 1. _Strangerites magnifolia_, Rogers; Trans. Assoc. Am. Geologists, p. 306, Pl. xiv. A species occurring in the Trias (?) of Virginia and North Carolina. 2. _Pecopteris falcatus_, Emmons; Geol. of N. Car., Pl. iv, fig. 9. The specimens are too imperfect to decide on the identity of this plant with _Saccopteris germinans_. ?3. _Pecopteris bullatus_, Bunbury; only in fruit; nervation obscure; identity not certain, but very probable. 4. _Otozamites Macombii_, Newb. At top of “red beds” or “gypsum formation,” at the base of the Cretaceous rocks, copper mines near Abiquiu, New Mexico. There is no doubt about this species, and it forms an important connecting link. ?5. _Pterozamites decussatus_, Emmons; specimens very imperfect. 6. _Pecopteris_, n. sp.; a very neat and peculiar species as yet undescribed. It may be the same as one badly figured by Emmons (Pl. II, fig. 1.) 7. _Alethopteris_, n. sp.; small fragments of the frond of a splendid new species. From this enumeration it will be seen that there can be but little doubt of the Triassic age of the formation in which these plants occur. A large lot of these plants, collected by M. Rémond, has been recently received, and among them are much better specimens of some of the species noticed by Dr. Newberry, and several quite new ones. These will also be examined, described, and figured within a short time. J. D. W.] The strike and dip of the clay shales in the different ravines vary considerably, but the dip is usually to the southeast. The superincumbent quartzites are more regular in their inclination. There are dykes of feldspathic rock cutting through both the coal and the shales. The following section represents, in an ascending order, the position of the coal-bearing strata in the Cañon del Retiro, near Los Bronces. 1. Coarse quartzites with conglomerates. 2. Conglomerate, 8 feet. 3. Argillaceous and schistose grits, 3 feet. 4. Clay shales, with impressions of plants, 8 feet. 5. Gray grits, 4 feet. 6. Bluish clay shales with ferns, 12 feet. 7. Coal, 2 feet. 8. Compact black clay shales, 5 inches. 9. Coal, 2 feet 6 inches. 10. Clay shales with leaves, several feet. 11. Coarse grits. Another section, measured at the foot of the Cerro de la Aguja, was as follows.